Research On DPF Modification Technology Of Diesel Engine

In recently years, the frequent occurrence of haze and other extreme weather in many big cities, have sparked people’s attention and concern of urban atmospheric environmental issues. In dealing with the urban atmospheric environment issues, the vehicle emission pollution has become the important and difficult point. Currently, the country Ⅳ stage diesel national standard has been implemented, but the emission pollution was from vehicles of the country Ⅲ stage mainly. Especially Ⅲ stage national standard of non-road mobile machinery was implemented for a short time. The non-road mobile machinery of I and II stage product pollution seriously. Therefore, reformation of old vehicles and non-road mobile machinery is urgent.In this study, engine bench testing, lug-down mode test, real-world tests and other testing methods were used to assess emission of road vehicles and non-road mobile machinery’s after DPF reformation. The main research contents and results in the paper are as follows:1)Bench test was done before DPF reformation, As studies shown, the mass filtration efficiency of PM can reach more than 80% averagely, and the number filtration efficiency of PM can reach 99% averagely. The emission of NO2 decreased significantly, or even disappeared completely. The emission of NOx almost unchanged after DPF reformation. Installation of DPF had little effects on CO emission.2) Research on PM and gaseous pollutants emission from vehicle after DPF reformation was done. The number filtration efficiency of PM can reach 99% averagely. The amount of particulate matter can be reduced in an order of magnitude. NO2 had dropped to 40%. The emission of NOx almost unchanged after DPF reformation.3)Research on PM and gaseous pollutants emission from non-road mobile machinery after DPF reformation was done. The number filtration efficiency of PM can reach 99% averagely. The emission of NOx almost unchanged after DPF reformation.